Radioisotope generators based on fajans adsorption on glass microspheres

Several radioisotope generator systems exist in which the carrier-free daughter product would precipitate if present in macro amounts at pH levels at which the parent is stable. Included among these are the Ge-68/Ga-68, Sr-90/Y-90, and Ca-47/Sc-47 pairs. In these systems chemical separation may be achieved by Fajans adsorption of the radiocolloidal daughter products onto surfaces such as activated glass microspheres at an appropriate pH, followed by washing to remove the parent solution and desorption of the daughter crop by acid washes. Investigation of the Ge/Ga and Sr/Y systems demonstrated that this solid phase extraction method is erratic, but can give daughter yields as high as 89% with separation factors up to 7,100 from parent isotope